Projection techniques known today can mainly be grouped in two types: Liquid Crystal Display (LCD) projectors and Digital Light Processing (DLP) projectors. The DLP projector was developed by Texas Instrument Co. It has a very small mirror installed on a micro chip called a Digital Micromirror Device (DMD) to reflect light and generate very bright and sharp projection images. Nevertheless, projectors that adopt LCD or DLP usually use one single lamp as the light source to project images. To obtain higher lumens, the projector needs a higher-powered lamp.
Lamps with high power result in shorter usage life and more power consumption. However, using a higher power lamp increases the costs of spare parts. Hence it is not an effective technical solution.
Therefore it is necessary to develop a solution that uses more than one lamp of relatively low power to achieve an equal amount of output lumens through an optical converging process to remedy the problems of high power consumption and low illuminating efficiency that occur to the higher power lamp.